DW735 Knives, Only One Cutting?

I looked at the knives on my DW735 the other day (not used much) and noticed only one of the knives seems to show any sawdust/pine pitch on and around it (The other two knives and the area on the head around them look practically new!).
This leads me to believe that only one of the knives is actually actually cutting or is doing the majority of the work. I marked the cutter head and flipped the knives. A week later the same knive shows the same amount of extrodinary use (the other two still look practically un-used).

Has any one noticed this on their DW735?

I emailed DeWalt and they sent me the standard (take it to an autherized DeWalt service center, which is 80 MILES from me) tech support answer (If my DW745 was a computer they probably would have told me to re-boot it!).

Thanks in advance

What does you stock look like when it somes out?

I am not sure if 'tear-out' is the proper term. Little gouges up to 1/4 inch long about 1/8 wide. On a 4 1/2 X 2 section there will be up to 20 of them. The gouges are random (i.e. not from nicked blades). This was done at 96CPI. Gouges are still present but not a numerous at 179CPI.

There are NO 'chatter' marks.

The above is true with both SYP and mahagony. Boards are dry (14% and 10% repecivly) and the grain was oreinted properly.

To clairify why I am asking:
1.) I do not do much work.
2.) I bought the DW735 about a year ago to replace a very old delta 12" bench top I picked up at an auction. It was pretty beat up.
3.) The conditions I am describing have always been true since the day I purchased the DW735 so I am contending it could not possibly be a wear issue.
4.) The DW735 does do a better job than the old Delta so I was satisfied.
5.) I recently got a Shop Fox 3Hp, 8", 4 Knive planer to replace an old 6" Grizzly.
6.) When I joint the same stock (at roughly 2" per second which equates to 179CPI on the cutter head) it produces a BY FAR (like 100% better) finish than the DW735.

This is what led me to looking at the DW735 Knives! Perhaps this is simply the best you can get from a DW735?

What I was hoping for was some people with DW735's to say 'My knives look the same' or 'My knives do not due that. Dust and pitch appear on all three knives, not just one).

Thanks!

Hi Robert, I wouldn't recognize a DW375 if it said Hi to me on the street, however...

Can you check the knife height from the bed surface?

On stationary planers you use a wooden block with two parallel surfaces, for example a short length of 1 X6.

Unplug the planer, put the block inside and slowly adjust the height until one knife barely touches the block when you rotate the cutterhead back and forth.

Take a felt pen and put a stripe on the knife so you can remember which knife it was.

Rotate the cutterhead to check the next knife, and see if it's set at the same height.

Repeat for all the knives, and check both sides of the planer to make sure it's parallel.

This should tell you if one knife is out of adjustment or not.

Regards, Rod.

No, that is not normal. Mine wear evenly.
When you turned the knives did you put them in the same place?
I am thinking you either have a defective knife or a defective head. If you move the knives around and the same knife wears then it is the knife; if the same position wears it is the head.

I had the same thing happen on a jointer once, but assumed I did a lousy setup. Since you don't do any setup on the 735, that obviously isn't your problem.

Just the fact that the gouges are random indicates something is cracked, loose or out of round with the cutter head but it's easy enough to move the blade blade to another position and eliminate the knives.

Quote:

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Originally Posted by Robert Sullivan

I am not sure if 'tear-out' is the proper term. Little gouges up to 1/4 inch long about 1/8 wide. On a 4 1/2 X 2 section there will be up to 20 of them. The gouges are random (i.e. not from nicked blades). This was done at 96CPI. Gouges are still present but not a numerous at 179CPI.

There are NO 'chatter' marks.

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I like Rod's technique for checking the blades. As I have a two-knife single-speed Delta 22-560 with quick set disposable knives. So I can't speak to whether the issue is knife related or not. I work with a lot of pine (for practicing my technique, setup, test runs, and prototyping). Pine usually produces stringy chips and breaks apart into little almost square pieces plus it tends to be on the stickier side and I have to clean my roller quite often during a day of planing pine.

If you feed a piece of stock straight into the planer, nicked knives will leave a high ridge the length of the board. A low or high knife will produce a wash board effect with periodic high ridge running the width of the board. Pieces and chips stuck to the rollers will tend to produce a tear-out look on the stock but in actuality is from the chip stuck to the roller being pressed into the face of the stock.


How clean are your rollers, beds, and tables?

With cutter marks 1/8" wide,if I understand you,only 1 knife is cutting.With sharp,even knives on that type of planer,you should see only very tiny cut marks. I have a Delta 12" which planes smooth as glass,and will actually plane some figured woods smooth that a larger planer would chip. My larger Bridgewood planer fills up my chip bin so fast,I just carry the little one outside and make mulch for my wife on the spot.

Thanks All,

First I followed Rod's advice. There seemed to be an almost imperceptable (read as it could be my imaginiation because I knew the knive I was questioning!) drag on my set up block on one of the knives. I swapped two of the three knives (changed their locations) so a different knive was in the position in question. While swapping I noticed no play in the seating of the knives vertical direction as would be expected with this sort of dispozable/self setting knife setup. To be sured tighened a little more than fingure tight on the knife hold downs and jammed the knives up against a 1/2 piece of stock to make sure pressure was excerted in the 'downward' direction (towards the head) in case there was any play in the seating. Again I went to Rod's set-up block suggestion and still perceived (i.e. Imagined?) a drag on the same knife position on the head.

NOTE to any DW735 owner's. Make sure your setup block fit's in between the rollers so the rollers do not end up sitting on it!

Ran the same stock I did before making very small cuts (less than 1/32) and though the problem has not gone away it is much better. With that said (much better) I am still not satisfied. I will now run some BF through this week and see what happens. I suspect at this point I have a problem with the cutter head as Wade and others have suggested. I will update this thread with the status a week from now, and then I am sure a final status since I am sure I am going to end up sending it to a DeWalt service center (Crap!).

Anthony, George:
1.) The table is clean.
2.) The rollers are clean.
3.) A better word four the 'Gouges' may in fact be 'pock marks'. They are completly random over a 4 foot length of stock. When I say the marks are up to 1/8 of an inch long I am saying that the 1/8 of an inch is running the length of the board, not the width.
4.) No ridges, no high spots, no wash board effect.

Thanks all.

Can't really help you with the original problem... But the "pock marks" sound an awful lot like tearout to me. Sometimes simply planing the board the other way through the machine will help... although sometimes with tricky grain I get tearout no matter which way the board is fed through.

Can you post a picture of the pock marks?

You have likely eliminated the knives as a cause, but to be certain, take all 3 knives out of the cutter head and lay them on the bench. Using a dial caliper, measure their width. They should be the same within about 2 thousandths. Then set the knives on top of each other, press the cutting edges of all three against a stop block (with another block of wood! These knives are razor sharp and will cut through a glove and into your hand instantly), and look at the alignment of the mounting holes. They should line up perfectly. If the knives fail either of these tests, the fix is simple, you have defectively manufactured knives.

If the knives are OK, then your cutter head was milled incorrectly. If you've bought this recently, I'd take it back to the store, and demand a refund/exchange. There is no excuse for you to have to put up with either driving 80 miles to a service center or paying to have it shipped there.

FYI - I've the 735. With sharp knives and with the machine set in the slow feed rate, the surface, while not finish-ready, is remarkably smooth.

I got my 735 back from a service center about a week ago with a new head on it. Works like a champ! Thanks to all for your input.